This invention relates to portable personal computers.
More particularly, this invention relates to a technique for improving the power consumption rate in portable personal computers.
Portable personal computers, particularly those of the type known as laptop computers, currently enjoy increasing popularity as an extremely useful business and personal aid across a wide cross-section of computer users. Continuing improvements in processing power, including faster processing speeds, increased memory capacity and improved I/O devices (such as faster internal modems) have led to a wider adoption of laptop computers for both business and personal use. The key ingredient to this success has been the continuing improvements in the processors incorporated into laptop computer systems: however, on average, as the processing power increases, the power consumption factor likewise increases. In addition, faster and more powerful processors typically generate so much heat that special cooling mechanisms must be incorporated into the computer--e.g. cooling fans, thermal cooling modules and the like. Since these necessary auxiliary devices themselves consume power, their presence raises the power consumption factor by an additional amount.
While the increase in power consumption due to faster, more powerful processors provides little or no disadvantage when the laptop computer is connected to an external power source (typically by means of an AC to DC converter or adapter), the higher power consumption factor reduces the useable duty cycle when the laptop computer is powered by an internal power source (typically a small rechargeable battery pack). A shortened useable duty cycle for a portable power source is a serious disadvantage in those cases in which the laptop computer user does not have access to an AC power source (e.g. while traveling on an airplane). One solution to this problem is to provide larger internal power sources or an extra battery pack in an accessory kit. However, this adds substantial weight to the laptop computer. This is a serious disadvantage since weight is one of the most important characteristics of a portable laptop computer and since users demand the lightest weight computer for convenience of traveling.